1. Field of the Invention
The present invention is broadly concerned with improved aircraft crew vision masks which can be rapidly donned during a smoke in cockpit emergency and which include a head-mounted display device such as a retinal scanning display device operably mounted on the mask and coupled with a source aircraft flight information (e.g., flight instrumentation) in order that flight information is directly scanned onto the retina of a wearer""s eye, thereby allowing the wearer to view the flight information notwithstanding the presence of cockpit smoke. More particularly, the invention is concerned with such masks which in preferred forms include automatic sensor-responsive and manual control capabilities for the retinal scanning device, so that the wearer may selectively turn the display on or off, or change the information input thereto.
2. Description of the Prior Art
Among the dangerous and even catastrophic emergencies encountered during aircraft flight is the existence of smoke in the cockpit. This stems from the fact that while the pilot may have an adequate source of breathable gas and his eyes may be protected from irritants, nonetheless he may be unable to see the instrument panel and have adequate vision through the aircraft windshield owing to accumulated smoke. Indeed, in the recent past two commercial airliners have been lost after the aircrew reported smoke within the cockpit, this occurring even though the crew successively donned oxygen masks.
One response to this problem is described in U.S. Pat. No. 5,202,796 and is referred to as the EVAS (Emergency Vision Assurance) system. In this device, a clear plastic airbag is provided adjacent the instrument panel. In the event of a smoke emergency, the pilot pulls a tab, which inflates the airbag. The pilot can then press his face against the inflated transparent bag in order to see the instrument panel. The size of the bag also inherently limits the field of view of the user. However, this relatively unsophisticated device presents a number of problems. First, the pilot must keep his face firmly against the inflated bag, which means that he cannot attend to other emergency conditions which may require attention. Furthermore, the device takes 15-20 seconds to deploy, which represents a rather significant time lag before any instrument vision is restored.
Conventional heads up displays (HUDs) have been used in civilian and military aircraft for a number of years, to display instrumentation and targeting information for example. These types of devices are not generally useful in a smoky cockpit situation, because dense smoke in the cockpit will prevent the pilot from actually seeing the display, or may disrupt system projection.
Head-mounted displays have been proposed in the past for use in various contexts. For example, retinal scanning displays (also known as VRD displays) have been suggested as vision enhancers in fire fighting equipment and the like. Retinal scanning displays differ from heads up displays and similar technologies in that an image is raster scanned directly onto the retina of user, as opposed to being projected onto another surface. See, e.g., U.S. Pat. No. 6,097,353.
U.S. Pat. No. 5,420,828 describes a viewing screen assembly for mounting on helmets or face masks, particularly in the context of fire fighter""s helmets. The device described in this patent is designed to accept video input from a remote person or location. U.S. Pat. No. 6,078,427 describes head-mounted displays for use with flight simulators, which may include a virtual retinal display device. U.S. Pat. No. 5,091,719 describes a helmet display for use on aircraft pilot helmets. This reference does not disclose the use of retinal scanning displays, nor is the problem of smoke addressed. See also U.S. Pat. Nos. 3,170,979, 6,157,291 and 6,137,457.
The present invention overcomes the problems outlined above and provides an improved aircraft crew vision mask equipped with a visual display device such as a retinal scanning display device and operably coupled with one or more sources of aircraft flight information in order to display such information as a part of a retinal scan during a smoke in the cockpit emergency. Generally speaking, the vision mask comprises a substantially transparent lens with a face seal disposed about and supporting the lens, and with a harness assembly for mounting the mask on the face of a wearer so that the wearer may look through the lens. The retinal scanning display device is operably mounted on the mask and is oriented to generate a retinal scan on a retina of the wearer.
Preferably, the mask is of the full-face variety and includes apparatus for delivery of breathable gas to the wearer. It is contemplated that the mask of the invention would be normally stowed in a location adjacent the wearer until an emergency develops; at this point, the mask may be grasped and pulled from stowage in the manner identical to present-day emergency oxygen masks. To this end, it is preferred that the mask be equipped with an inflatable harness which expands to a relatively large size upon removal of the mask from stowage, in order to facilitate donning of the mask.
The visual display device is preferably secured to the mask exterior at the face seal of the mask and includes an output substantially at the wearer""s eye level. In one form, the RSD depends from the face seal of the mask, and has an output at eye level.
In order to activate the display, the preferred vision mask has a sensor which detects a parameter indicative of visible smoke or conditions which precede the generation of visible smoke, such as an ion detector. The sensor is coupled with the flight information source(s) and the display for this purpose. Also, a manual controller is also provided, which gives on/off capability and also the option of switching between different information inputs. For example, the usable information may be selected from the group consisting of aircraft airspeed, attitude, altitude, heading, vertical speed, navigation information, video from camera(s) external to or within the aircraft, flight manual information, and combinations thereof, and the wearer may wish to switch between various ones of these inputs.